AttachExpert: attach an EA with inputs to a chart from code - libreria per MetaTrader 5

AttachExpert.mqh attaches an Expert Advisor to a chart from MQL5 code, with the inputs you choose and with "Allow Algo Trading" on or off. MQL5 has no function for this; the library writes a template with an <expert> block and applies it with ChartApplyTemplate().

Usage

#include <AttachExpert.mqh>

long chart = ChartOpen("EURUSD", PERIOD_H1);
CExpertInputs in;
in.SetInt("InpValue", 42);
in.SetDouble("InpRatio", 1.25, 2);
in.SetString("InpText", "hello world");
in.SetBool("InpFlag", true);
AttachExpert(chart, "MyFolder\\MyEA", in, true);   // MQL5\Experts\MyFolder\MyEA.ex5

• Inputs that you do not set keep their default values.
• The template is applied asynchronously. By default AttachExpert() waits up to 10 seconds until the EA runs on the chart (CHART_EXPERT_NAME); pass waitMs = 0 to return at once, for example from an Expert Advisor.
• Do not apply it to the chart of the calling Expert Advisor: the template would replace the caller.
• Whether the attached EA can trade also depends on the AutoTrading button of the terminal.

Example

The script AttachExpertExample.mq5 opens a chart and attaches the Moving Average example EA (Experts\Examples\Moving Average) with chosen inputs. Put AttachExpert.mqh in MQL5\Include and the script in MQL5\Scripts.

Checked

A test EA attached on M15, H1, H4 and D1 charts reported the inputs it received (int, double, string with a space, bool) and whether it was allowed to trade; all matched (picture 1).